A client just had brand new cladding installed around his pool. These are colored concrete slabs installed with grout in between them. They picked what color they like out of the catalog and after the contractor installed them the color was quite a bit lighter than they were hoping.
I guess the Contractor tried to acid wash it (no idea which product to used) and it made it lighter not darker like he thought it would. It’s weird though when the stone is dry the color of the line is darker but when I put water on it the color of the line is lighter (see the pictures for reference, one of the pictures shows most of the stone wet but the top left is dry).
They gave me a sample piece to work on but hoping to get some feedback before I mess with it. It is an integral mix, but it looks to me like they added a layer on top of more color. There are weird lines on some of the pavers next to the grout, attached are some pictures of the sample piece and close-ups of the area in question. Anyone have any idea what could cause this and how I might be able to make it look uniform?
Are you sure that’s not polymeric sand? Looks like staining from the binder in the poly washing out because of a bad install. Since it sounds like this is recent work, the contractor should fix it. If you didn’t create the problem, don’t take on the headache of fixing it. You’re basically looking at redoing the entire job.
I have no idea what they used for the grout, it probably is polymeric sand, maybe that’s the reason for the lines that look different than the rest of it?
The other issue is after installation the color looked different than they were expecting. Attached are 3 more pictures, one of them shows the color they picked (Taupe), and the other two are pictures of the back side of the sample pieces that were not installed and no one knows for sure if he acid washed these or not. The third picture in the original post was the edge view of one of the extra pieces not installed, these other two are of the backside where you can see a significant difference in color. It almost looks like it is wet but it is bone dry. Is that because they added more color on top of the integral mix and it just ran down underneath it a little bit? Do you think sealing it will make all of the color uniform? I think that sealing it would help darken all of it but I’m not sure if it would help the lines that look different since they go from darker to lighter when it is wet.
My guess is they either used too much sand in the joints or overwatered it, which caused the polymer to rise above the joints. That polymer and water mix likely settled on the surface of the stones edge and dried, creating the line you’re seeing… it looks very typical of a liquid stain. When the stone is dry, the stained area appears darker, but when it’s wet, the polymer blocks water absorption, acting like a sealer, which makes it look lighter than the rest.
The color variation along the edging is probably from either adding extra pigment to the top coat or from the acid wash stripping pigment and causing it to run down the edge with gravity. Either way, whatever the contractor did… whether it was a bad install, poor sealing, or an aggressive acid wash altered the color from what it should have been.
Again, if this isn’t something you caused, walk away. The homeowner should be holding the original contractor responsible. If you do take it on, price it like a full re-do. There’s no simple, cheap, or reliable fix here… throwing good money after bad will just end with you losing money on this job.
